Effect of BCG and allogeneic tumour cells on adenovirus type 12 tumorigenesis in mice

HAMSTERS and mice inoculated at birth with tumour viruses have been used in studies of the prophylactic effects of various treatments during the latent period. The incidence of primary tumours in hamsters infected at birth with SV40 is reduced if the virus is inoculated during the latent period^1-3. Similar administration of adenovirus type 12 also inhibited the induction of tumours by SV40⁴; this was taken as an indication of a cross-reaction between the tumour-specific transplantation antigens (TSTA) of SV40 and adeno 12 virus tumours. X-irradiated SV40 tumour cells which did not contain infectious virus were also effective in reducing the frequency of primary SV40 tumours when given at various times before tumour development^2,5.